Available topics of doctoral thesis:

Effect of radiation upon the progress of corrosion in iron-based materials for nuclear installations

This work concentrates upon study of mutual correlations between structural and magnetic arrangement in materials with application potential in nuclear installations. Advanced multiphase iron-based materials, the so-called amorphous and nanocrystalline alloys as well as conventional stainless steels will be investigated. Attention will be focused on description of microstructure and its modifications caused by corrosion. Progress of corrosion will be studied as a function of the degree of radiation damage of the investigated materials after their exposure to ions and neutrons.

In this project, mostly nuclear-physical methods of analysis will be employed. As the principal method, Mössbauer spectrometry in transmission geometry will be used besides to its surface sensitive techniques like CEMS and CXMS. The latter will enable investigations not only of the bulk but also of the surface behaviour of the materials under study. In addition, neutron activation analysis and magnetic measurements with SQUID will be also used.

Ing. Jan Rataj, Ph.D.

Experiments with pulsed neutron source at VR-1 rector

The goal of the thesis is a study (experimental and theoretical) of the VR-1 reactor response to various operating conditions of pulsed neutron source. Furthermore, the next goal is an application of methods of pulsed neutron source in order to determine kinetic parameters of the VR-1 reactor.

RNDr. Vladimír Wagner, CSc.

Study of neutron reactions important for advanced nuclear systems

Future generation IV reactors, accelerator driven systems and thermonuclear reactors will produce intensive fluxes of relatively high energy neutrons. The knowledge of cross-sections of neutron reactions with fuel, construction materials and neutron activation detector materials are very important for this reason. Experimental data on threshold neutron reactions with energy higher than 10 MeV are often very scarce. The Nuclear Physics Institute of the CAS has several quasi-monoenergetic neutron sources with energies up to 38 MeV based on the cyclotron. A new cyclotron producing intensive beams has been recently installed here and new neutron sources are developed there. We use also other neutron sources with higher energies in Europe (for example neutron source in Uppsala, Sweden). The PhD thesis is focused on the experimental measurement of neutron cross-sections by means of activation methods based on the gamma spectrometry. The obtained data are used for benchmark studies of nuclear reaction models and codes for description of neutron reactions (for example code TALYS).

The accelerator driven systems (ADS) should be promising future nuclear facilities to burn up spent nuclear fuel. They consist of a relativistic proton or deuteron accelerator and a heavy target. Spallation reactions of relativistic light ions on the heavy target produce intensive neutron fluxes. The effective transmutation of actinides in the subcritical blanket around such a target is enabled by these neutrons. The MYRRHA project will be a prototype of such a facility to be built in Belgium. Development of future nuclear transmutor designs needs benchmark of codes describing neutron production and transport, and also transmutation efficiency. Such a benchmark is made possible by means of experiments with more simple set-ups testing various parts of ADS. Lead or uranium target inside uranium blanket with actinide samples is irradiated by JINR Dubna (Russia) accelerators generating relativistic proton and deuteron beams. The PhD thesis will be focused on neutron field measurement inside such set-ups by means of activation detectors. The obtained experimental results will be compared with simulations by means of MCNPX and FLUKA codes.

Preparation of nuclear data for full-core calculations of research and power reactors

Study of macroscopic nuclear data and their preparation for full-core calculations of research and power reactors (theoretical studies and modeling as well as experiments and comparison with experimental results) for different reactor types and using different computational codes (SCALE, SERPENT, PARCS, DYN3D) and developing appropriate methodologies .